Steam turbine lubricant



United States Patent STEAM TURBINE LUBRICANT Hans C. H. Jensen, East Hendred, near Wantage, England,

' reduce this tendency to form emulsions. Thus this invention comprises a lubricating oil composition adapted to lubricate steam turbines containing a small proportion of a sulphonated fatty acid.

5 The amount of sulphonated fatty acid that should be asslgnm' 2 2 g and Engmeermg Company added is quite critical, but is readily determined by exa corpora on o e aware periment. It is normally less than 5% and preferably is No Drawing. Application November 26, 1954 in the range of 0.001 to 0.2%; the proportions in excess Serial No. 471,529 of 2% should be observed with care since in these cases Cl i priority, application Great Britain the sulphonated fatty oil may in fact promote emuls1on December 9, 1953 fonflanon' i To determine the proportion of sulphonated fatty oil 2 Claims. (Cl. 252-33.4) to be used, all that is required is that the oil and the u sulphonated material should be agitated with water and P lBVelltlOH relates to 116W Improved lubflQams the separation of the resulting emulsions should be noted. particularly adaptedfor the lubrication Of steam tUIbIHC S. Generally peaking any fatty oil may be sulphonated h lubrlcants Of is lnventlon are y thfilf to produce a useful additive according to the present infieedom from formlng Stable e111111510118 011 agltatloll Wlth vention. However, castor oil is the preferred fatty oil Waterand the product of sulphonation Turkey-red oil, is very The Stem} l 15 all lncreaslllgly P p P im 2O well-known commercially. This may be and commonly mover paltlcularly useful f mal'lne P P is partially or completely neutralised to make a propor- The lubrwaflon of the steam turbme however presents a tion of the alkali metal salt, e. g. sodium or potassium, number of problems. The turbine itself has a very high or th ammonium lt, speed and therefore there must be associated with it a Th ffi of hi invention i if f h reduction gear-box to reduce the number of revolutions accompanying table, wherein the effect of .l% of Turke P mlnlltefransmlfled the P peller. red oil is given on 4 turbine oil compositions:

The lubricant in a steam turbine circulates through the system and during circulation inevitably comes in con- Results of laboratory demulsibility tests tact with water. In the system it is normal to have a separator to separate any entrained water, and it is es- P f Of p and 180 test sential that the lubricant frees itself of all entrained water 011 are emulslfied m a am Mixmaster for 10 minutes in this separator. The separator is usually either a filter, at IIlaX- P. The emuls1on formed 18 Centrlfilged 111 a centrifuge or a separating drum. a Gallenkamp centrifuge for 10 minutes at max. speed Generally speaking, since the lubricant has to be cir- (g-value=l,000). All operations are carried out at room culating in the system for a considerable length of time temperature.

Test Oil Test Result; Code Additives Amount of Sludge Type Base Oil Unknown.-- Unknown Considerable.

. d (1 None.

Considerable. D C 0.1% '1. R. do None. E E. P. Turbine Oi1 Solvent extracted 0.4% 2,4-di t butyl p cresol 1% polyethylene glycol Considerable.

' ate oil. 400 di-trl-rlcinoleate. 0.05% Proprietary rust preventive. 0.001% silicone antifoam agent. 2% Tributyl phosphate. 1.2% isopropyloleate. F E 0.1% T. R. O (10 None. G E. P. Turbine Oil.. 0.4% 2, 4, (it t butyl p cresol. 0.05% polyethylene glycol Considerable.

di-tri-rieinoleate. 1% hexachlorocyclo hexane. H G 0.1% T. R. 0... .do None.

1 Turkey-red oil.

it is necessary for it to contain various additives. These additives are required in order to reduce the oxidation tendencies of the oil under the high temperature oxydation conditions to impart to the lubricating oil properties that will result in the metal surfaces with which it is in contact being resistant to corrosion, to reduce its tendency to foam and to increase its ability to lubricate highly loaded gears and bearings.

A disadvantage of these additives is that generally speaking, whereas they fulfil their prime function satisfactorily, they tend to incite the lubricant to form emulsions in the presence of water. These emulsions are sometimes very intractable and result in the separating system functioning imperfectly. As a result water can circulate in the system and considerable damage can be done, and in some cases the separator clogs and the system suifers from oil starvation.

It has now been discovered and it is the subject of this invention that certain sulphonated fatty acids when added in controlled proportions to such turbine oils considerably It will be seen that whereas with each of the 4 typical turbine oils tested a considerable sludgy emulsion of doughy consistency was formed on the interface between the oil and water layers, with the use of Turkey-red oil this emulsion was eradicated.

The base oil with which this invention is concerned can be any conventionally used mineral oil adapted for the lubrication of steam turbines. That is to say it should contain additives to impart resistance to oxidation and it should contain additives to protect from corrosion metal surfaces with which it comes in contact.

The anti-oxidant will normally be a phenol or substituted phenol or amine or organic sulphur containing compound. It is particularly preferred to use alkylated cresols for example 2,4-di t butyl p cresol. The rust preventative additives are organic polar compounds soluble in mineral oil. They normally comprise a molecule having a hydrophobic and a hydrophilic portion.

What I claim is:

1. In a mineral oil composition, adapted for lubricatienef steam turbine ecmprisin a blend of a. solvent extracted I distillate oil, anoxidation-inhibiting amount of redueethe emulsifying tendency of said composition, of

a sulfohated castor oil,

2.The"improyement according .to claim 1, wherein said oxidation inhibiting amount constitutes 0.4% 2,4, di t butyl p"cresol, Sirl'foam inhibiting amount constitutes 0.05%" polyethylene glycol di tri ricinoleat'e' and said' References Cited in the file of this patent UNiTED "STATES PATENTS 1,677,389 Howes July 17, 1928 2,390,491 Bennett Dec. 11, 1945 2,390,492 Bennett Dec. 11, 1945 2,528,466 Borsoff et a1. Oct. 31, 1950 OTHER REFERENCES Performance of Lubricating Oils, by Zuidema,-Reinhold Pub. (30., 1952, pages 129-435 pertinent.

National Adyisory Committee for Aeronautics Wartime Report,'Foaming of Aircraft-Engine Oil's, September 1944, as AdvanceRestricte'd Report 4, 105, pages 65 rust inhibiting amount constitutes '1%--hexachioroeye1o '15 "and 74 pertinent;

hexane. 

1. IN A MINERAL OIL COMPOSITION, ADAPTED FOR LUBRICATION OF STEAM TURBINES, COMPRISING A BLEND OF A SOLVENT EXTRACTED DISTILLATE OIL, AN OXIDATION INHIBITING AMOUNT OF 2,4 DI T BUTYL P CRESOL, A FOAM INHIBITING AMOUNT OF HEXACHLOROCYCLO HEXANE, AND A RUST INHIBITING AMOUNT OF POLYETHYLENE GLYCOL DI-TRI-RICINOLEATE, WHEREIN THE PRESENCE OF SAID INHIBITORS TEND TO INCITE EMULSION FORMATION, THE IMPROVEMENT WHICH COMPRISES THE ADDITION TO SAID LUBRIATING COMPOUND A MINOR PROPORTION, SUFFICIENT TO REDUCE THE EMULSIFYING TENDENCY OF SAID COMPOSITION OF A SULFONATED CASTOR OIL. 